Nitrile hydrogenation catalyst

ABSTRACT

A HYDROGENATION CATALYST OF HIGH ACTIVITY, GOOD CRUSH STRENGTH AND STRONG RESISTANCE TO DISINTEGRATION WHEN EMPLOYED IN A FIXED-BED HYDROGENATION PROCESS COMPRISING A HYDROGEN-REDUCED MIXTURE OF SODIUM SILICATE AND COBALT OXIDE IN A WEIGHT RATIO OF SODIUM SILICATE:COBALT OXIDE OF ABOUT 1:1 TO 1:9.

United States Patent Oflice 3,728,284 Patented Apr. 17, 1973 3,728,284NITRILE HYDROGENATION CATALYST Jelferson W. Reynolds, Kingsport, Tenn.,assignor to Eastman Kodak Company, Rochester, N.Y. No Drawing. FiledJuly 29, 1970, Ser. No. 59,368 Int. Cl. B01j 11/22, 11/32 US. Cl.252-459 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to anovel hydrogenation catalyst composition useful particularly in thehydrogenation of nitriles to amines.

Amines, particularly primary and secondary amines, have found extensiveutility in chemistry and the literature is full of reference to methodsfor preparing the same. One of the common methods of preparing amines isby the hydrogenation of nitriles in the presence of a fixed bed of solidcatalyst. A wide variety of hydrogenation catalysts have been employedin this reaction but none have been entirely free from criticism. Aserious fault of many fixed-bed solid hydrogenation catalysts is theirinadequate crush or mechanical strength. For instance, commerciallyavailable fixed-bed cobalt or nickel catalysts are quickly softenedunder nitrile hydrogenation conditions to the point of disintegration.Disintegration is, of course, undesirable since it results in pluggingof the reactor bed with consequent loss of efficiency. Other criticismsof conventional nitrile hydrogenation catalysts have been cost,inadequate catalyst life and complicated preparation procedures.

One of the objects of the invention is to prepare a hydrogenationcatalyst of high activity, improved physical strength such as goodcrushing strength and a strong resistance to disintegration whenemployed in a fixed-bed hydrogenation process.

Another object of the invention is to provide a catalyst compositionthat is easily prepared from readily available materials.

Yet another object of the invention is to prepare a catalyst compositionhaving a long active life in the preparation of amines by thehydrogenation of nitriles and which catalyst does not require sinteringor fusion in its preparation.

A further object of the invention is to provide a process for theproduction of high yields of amines by the hydrogenation of nitriles.

These and other objects of the invention are obtained by a catalystcomposition comprising a hydrogen-reduced mixture of sodium silicate andcobalt oxide in a weight ratio of sodium silicatezcobalt oxide of about1:1 to 1:9, preferably about 1:1.5 to 1:5.

The catalyst composition of the invention may be easily prepared bymixing an aqueous sodium silicate solution and an oxide of cobalt(calculated as C) in a weight ratio of dry sodium silicate to cobaltoxide of about 1:1 to 1:9, preferably about 111.5 to 125, forming theresulting mixture in macrosize particles, drying the macrosize particlesand subjecting the macrosize particles to hydrogen reduction. Any cobaltoxide may be used and cobalt oxide in a hydrate form such as cobaltoxide hydrate is preferred. Preferred sodium silicates are those whereinthe mole ratio of Na O:SiO is about 2:1 to 1:5.

Formation of the mixture of sodium silicate and cobalt oxide intomacrosize particles may be by suitable methods such as extrusion,pelleting, tableting and the like. The preferred method is by extrusionsince the paste-like mixture of the composition may be extruded withoutany complicated intermediate treatments such as washing or drying. Themacrosize particles generally have diameters of about to inch andlengths of about ,4, inch up to about /2 inch or more.

After the macrosize particles have been properly dried, they aresubjected to hydrogen reduction in accordance with methods well known inthe art. The reduction temperature generally employed is about 300 to500 C. Complete reduction is not necessary to obtain a catalyst havingthe desired activity and physical strength and, in fact as will be shownin the working examples below, incomplete reduction appears to provide afinished catalyst not only equal in activity to a completely reducedcatalyst but of greater durability. It should be understood thatpreparation of the catalyst of the invention does not require treatmentssuch as sintering, fusing, etc., usually necessary to activate thecatalyst.

Although the catalysts of the invention are useful in hydrogenationreactions generally, they are particularly useful in the hydrogenationof nitriles. Any monomeric nitrile having the general formula R(CEN) iscatalytically hydrogenated by hydrogen gas to primary and secondaryamines in the presence of the catalyst of the invention. In the abovegeneral formula, 11 is any whole number from 1 to 4 inclusive,preferably 1 to 2 and R may be any hydrocarbon radical substituted orunsubstituted, preferably of 1 to 18 carbon atoms. R, therefore, may bealiphatic, alicyclic, aromatic, aliphatic-aromatic, aromatic-aliphatic,or heterocyclic structures including, by way of example, hydrocarbonradicals and substituted hydrocarbon radicals containing substituenthydroxyl, keto, carboxyl, halogen, aldehyde, ether, amine, amide, imide,nitro, nitroso and the like groups in any combination. Furthermore, itis to be understood that the presence of such hydrogen-reducible groupsas ethylenic or acetylenic unsaturation in the nitrile does not makesuch nitriles inoperative for the purposes of the invention.

Illustrative of typical nitriles which can be hydrogenated in thepresence of the catalyst of the invention to provide the primary andsecondary amines include, but are not limited to, acetonitrile,propionitrile, butyronitrile, isobutyronitrile, capronitrile,caprylonitrile, myristonitrile, lauronitrile, stearonitrile,acrylonitrile, crotononitrile, hexenonitrile, 3-octenenitrile,oleonitrile, tridecanenitrile, Z-butynenitrile, 2,4-pentadienenitrile,l-cyclopentanecarbonitrile, 1-cyclohexanecarbonitrile,1,3-cyclopentadiene- S-carbonitrile, succinonitrile, adiponitrile,sebaconitrile, 1,4-dicyanobutene-2, 1,4-dicyanobutene-l, 4,4-dimethyl-2-heptene-1,7-dinitrile, dodecanedinitrile, 1,3,5-pentanetricarbonitrile,1,4 cyclohexanedicarbonitrile, 1,4 cyclohexanetetracarbonitrile,1,1,3-cyclohexanetripropionitrile, benzonitrile, Z-naphthonitrile,isophthalonitrile, terephthalonitrile, 1-phenylpropionitrile,trimesonitrile, u-ethyl- B-oxocapronitrile, isonipicotonitrile, S-yrimidinecarbonitrile, 2-cyano-3-heptenoic acid, ot-cyanoacetamide,p-cyanobenzaldehyde, u-cyanoglutarimide, a-hydroxyisobutyronitrile,2-benzimidazoleacetonitrile, phenylacetonitrile, valeronitrile, ethylcyanoacetate, phenoxybutyronitrile, cyanoacetamide, malononitrile,3-butenenitrile, cyanoacetic acid, undecanenitrile,fl-isopropoxypropionitrile, fl-methoxypropionitrile, toluonitrile,anisonitrile, fluorene-9,9-bis (propionitrile) and the like.

The amount of catalyst employed in the fixed-bed nitrile hydrogenationsof the invention is, in all instances, a catalytic amount.

The fixed-bed hydrogenation of the nitrile is generally conducted at atemperature of about 50 to C. and

at a pressure of at least 250 p.s.i., usually up to about 3000 p.s.i. orpossibly more. It is to be understood, of course, that the optionaltemperature and pressure employed depends somewhat upon the nitrile andthe partie- 4 EXAMPLE v A paste which contains 30% sodium silicate on adry basis is prepared from cobalt oxide hydrate (61% cobalt) fromShepherd Chemical Company and an aqueous soular catalyst employed. Inany case, a suitable temperature and pressure will be chosen whichpromote an 5 gigfil igs g g 3 33 gfis f i g i?g' acceptable Teactlonrate formed into inch extrusions and dried at room tern odyantageously,ammoma 1S fntroducefi to the hydro perature. 'Ihe extrudates, cut to Ato inch, are slowly genatlon Order P uPPreSs slfie reactlons' w driedfurther in a tube furnace in nitrogen. Hydrogen is P Y 1S Prawnt themole ratlo of 10 gradually introduced into the nitrogen stream to themtnle f about 2:1 material, and it is finally reduced 2 hours inhydrogen at An inert organic solvent or diluent is not necessary but QThe bulk density of the resulting black catal st may be employed ifdesired and may be advantageous is 30 lb./cu. ft. and its crushingstrength is4pounds y if where h relzwtkzn ii i g fmi l The followiiigexamples are included to demoiistrate s an la y any organic so ven oruen w 1c 18 mac we a both with respect to reaction with the Nazozsioycoo:tctgity and durability of the catalysts in nitrile hydrocatalyst andthe nitrile will be satisfactory. Suitable inert organic solvents ordiluents include, by way of example, EXAMPLES V-IX methanol, ethanol, -PP L methyl acetate, bflinlener Various nitriles are hydrogenated in thepresence of a 191116116, cyclohexane, Peptane, Petroleum ether,.dloxanei 20 fixed bed of the catalyst of Example I to the correspondingdlethyl ether and the llke- T amount of such Inert Q saturated diaminesby the following general procedure: Vent d11uent an Vary Wldely, butQhould be m The autoclave is charged with the nitrile dissolved in anamollpt Whlch w l greatly lncreflse P Y inert solvent and the catalystbasket containing the catalyst costs or interfere with isolation of thedesired primary is connected to the autoclave Coven The autoclave is andsecondary amine products. The process of the purged with nitrogen,sealed, charged with ammonia in vemlon y be out as a batch P Q as a fourof the five runs and placed in the magnetic stirrer 5011011110118Semlc011t111110115 P as barricaded in a cubicle. The magnetic stirrer isstarted T followlllg examples fllfthel' Illustrate P P and the contentsheated to reaction temperature. The sys- Tatlon of the catalysts of themventlontem is pressurized by hydrogen to the desired pressure andEXAMPLE I nl laintained at this pressure by hydrogen additions during te reaction period. At the completion of the reaction 20% Sodlumslhcate'cobalt (calculated as COO) the stirrer and heater are turnedoff, the autoclave cooled A paste is prepared from 149.5 g. of sodiumsilicate to 50 C., vented and the reaction product and catalyst solution(38.8% by weight aqueous solution of 1 Na O: removed. The product isanalyzed by gas chromatography 3.25 SiO and 300 g. of cobalt oxidehydrate (61% and the catalyst examined. The hydrogenation conditionscobalt) and extruded into A inch extrusions. The extruand results aresummarized in Table 1 below. Portions of sions are dried at roomtemperature and then slowly dried the catalyst of Example I are used tohydrogenate fluorenefurther in a tube furnace. The dried material isreduced -P P L4-CYCIOhBXaHBdiCBIbO- in hydrogen at 350 C. to provide acatalyst having a bulk nitrile (CDN) and4,4-dimethyl-2-heptene-1,7-dinitrile density of 28 lbs/cu. ft. and acrushing strength of 2 (DHN). The conditions and results of thesehydrogenapounds. tions are also reported in Table 1.

TABLE 1 Ex. Catalyst 8 Nitrlle i i h i a'. PLGSISJIEE? ll l l t l ll llil iii s? Solvent H ggrig it i n v 20% sodium FBN Gal-- 43 125 1,00010=1 570 2) Z-propanol- 04 Good.

silicate-cobalt. toluene.

d 1.51--. 48 125 600-1,000 None 200 Toluene 53 Do. 1.51 301 1251,0001,500 101 1,000 (5) do 05 D0. Gal.-- 205 125 1, 000 10:1 1,140 (4)2-propanol- 0:100 Do.

toluene. 1l 4 125 600 10:1 30 2-propanol 93 Do.

Used 15 g. of catalyst.

FBN=Fluer rene-9,9-lois(3-propiorutrile);CDN=1,4-cyelohexanedicarbonitrile; DHN=4,4-dimothyl-2-heptene-l,7-(1initrile.

Run length was normally 4, 24 or 48 hrs.

Total amount of nitrile is given; more than one charge is indicated inparentheses.

EXAMPLE I I sodium silicate-cobalt (calculated as C00) The procedure ofExample I is repeated using twice as much sodium silicate solution withthe cobalt oxide hydrate. The resulting hydrogen-reduced catalyst has abulk density of 72 lbs/cu. ft. and a crushing strength of 10 pounds.

EXAMPLE III 20% sodium silicate-cobalt (green) and 20% sodiumsilicates-cobalt (black) (calculated as C00) 1 l. autoclaveml., 1.51.autoclave-500 ml. and 1 gal. autoclave 1,500 ml. per charge; ratio of2-propanolztoluene was 1:4.

fActiyity 1S determined from percent diamine percent aminomtrile in theproduct.

As can be seen from the data in Table 1, the catalyst of the inventionis active for the hydrogenation of huerene-9,9-bis(3-propionitrile), 1,4cyclohexanedicarbonitrile and 4,4-dimethyl-2-heptene-1,7-dinitrile andthat the condition of the catalyst on completion of the hydrogenationsis good. The olefin bond in the latter nitrile is also hydrogenated.

EXAMPLES X-XI Flourene-9,9-bis(3-propionitrile) (FBN) is hydrogenated asin Examples V-IX in the presence of fixed beds of both the black andgreen catalysts of Example III. The hydrogenation conditions employedand the results obtained are reported in Table 2.

The data of Table 2 shows that both catalysts exhibit high activity andthe green catalyst, that is, the partially reduced catalyst is perhapsmore durable. The green catalyst was not expected to be active.

TABLE 2 I Auto- Time, Temp., Pressure, Moles NHQ; Nitrile, Activity,Catalyst Ex. Catalyst Nitrile b clave hr. 0. psi. moles nitrile gms.Solvent I percent condition X 20% sodium FBN 1.51..- 96 125 1, 500 1011400 (2) To1ue11e.---- @100 Good.

silicate-eobalt (Green). XI 20% sodium FBN Gal... 96 125 1,500 :1 570(2).. ..d0 r0100 Fair to silicate-cobalt good.

(Black).

N o'rE.Footnotes a-i, see Table 1.

EXAMPLE XII 0 I claim:

Fluorene-9,9-b1s(3-prop1onrtr1le) (FBN) is hydrogen- I Med as inExamples in the presence of a fixed bed 1. A hydrogenation catalystresistant to disintegration of the catalyst of Example II. in nitrilehydrogenations comprising non-sintered macro- EXAMPLE XIII sizedparticles of a hydrogen reduced mixture of sodium A 15-g. portion of thecatalyst of Example 1V in a wire silicate and an oxide of cobalt whereinthe weight ratio of basket is tested in the hydrogenation of 100 g. ofDHN dissolved in 400 ml. of 2-propanol using a 1.5-1. autoclave Sodiumslhcate to the oxlde of cobalt figured as 18 equipped with a magneticstirrer capable of being turned from about 1:1 to about 1:9. at 1000r.p.m. Ammonia is added to the autoclave to give 20 a molar ratio of 10ammoniazl nitrile. The hydrogena- The catalyst composmon of Glam 1wherein the on conditions employed and the results f h hydrogenaweightratio of sodium silicate to cobalt oxide is 121.5 tion of Examples XIIand XIII are shown in the following to 1: Table 3.

TABLE 3 Auto- Time Temp. Pressure Moles NHa; Nitrile, Acti it I t 1 Ex.Catalyst Nitrile b clave hrs 0: psi: moles nitrile gms. Solvent eiceiitgZZigg- XII 40% sodium FBN 1.51...- 48 125 1,500 10:1 200 Toluenc 50Good,

silicatecobalt. XIII 30% sodium DHN 1.51.-.- 48 100 600 10:1 100Z-propanol... De.

silicatecobalt.

Norm-Footnotes a-l', see table 1. This data of Table 3 shows that the30% and 40% sodium silicate-cobalt catalyst of the invention are active35 3, The t l t o ositi of l i 2 h i th and durable fl hydfogenatloncatalystsdium silicate is present in an amount of about 20 to 40%EXAMPLES XIV-XVIII by Weight. -p qp 9 and 4. The catalyst composition ofclaim 3 wherein the somethyl-Z-heptene-1,7-dimtr1le (DHN) arehydrogenated 40 TABLE 4 Auto- Time, Temp. Pressure Moles NHs' Nitrile dA ti u; I am; 1 t

Ex. Catalyst 1 Nitrile clave hr. 0: psi: moles nitrile gms. Solventpereei it congitiifm XIV Girdler G67RS FBN Gal... 48 125 750 10:1 2852-propanol- Dlsintetoluene. grated. XV Girdler G67HS FBN 1.5l. 24 1,00010:1 200 do 86 D XVI Girdler G69RS- DHN 1.51... 48 100 600 101 1002-propanol 89 Do. XVII Harshaw Ni-3210-- FBN 1.5 I.. 48 100 1,000 10:1200 Zignfpanol- W100 Do.

0 116118- XVIII American Cyan- DHN 1.51...- 144 100 600 5:1 2002-propanol.. 82 Do:

amid Aero 295.

N ore-Footnotes 214, see table 1. as in Examples V-IX in the presence ofa fixed bed of dium silicate is present in an amount of about 20% byvarious commercial catalysts. The hydrogenation condi- Weight tionsemployed and the results of the hydrogenation are 55 References shown inthe above Table 4. UNITED STATES PATENTS The data of Table 4 shows thedisintegration of the Suessellguth e131- 260-563 D 195 Kimberlin, J1.252-459 X various commercial catalysts and by comparison with the2407247 9/1946 gg 252 459 previous data emphasizes one of the advantagesof the 50 2 941,958 6/1960 Connor Jr et al 252459 X catalyst of thisinvention. 3,297,616 1/ 1967 Fisher, In, et a1. 252-459 X The inventionhas been described in considerable detail with particular reference tocertain preferred embodiments CARL DEES Primary Examinfir thereof, butit Will be understood that variations and mod- 65 US CL X'K ificatronscan be effected within the spirit and scope of 252 454; D the 1nvent1on.

